A compact 0.8–6GHz fractional-N PLL with binary-weighted D/A differentiator and offset-frequency Δ−Σ modulator for noise and spurs cancellation

A compact, low power and global-mismatch-tolerant 0.8-6GHz fractional-N PLL covers IEEE 802.11abg, PCS/DCS and cellular bands by using a binary-weighted 2 nd order digital/analog differentiator (DAD) to achieve 2 nd order mismatch shaping and reduce the quantization noise by 25dB, and using a 3 rd order offset-frequency Δ-Σ modulator to reduce in-band spurs by 20dB in simulation and 8dB in current single-ended practice.